Hypertrophic Pyloric Stenosis Case Study
Mr. and Mrs. B arrive in the emergency department with their 5-week-old infant, S. B.
As the triage nurse, you ask the couple why they have brought S. B to the ED. Mrs. B. states,
“My baby breastfed well for the first couple of weeks, but has recently been throwing up all the
time, sometimes a lot and really forcefully. He looks skinny and is hungry and fussy all the
time.” You determine that the couple is homeless and has been living out of their car for the
past month. S. B. has had no primary care since discharge after delivery.
1. What additional information will you need to obtain from Mr. and Mrs. B?
Your primary assessment of the infant reveals the following: S. B. is alert and fussy and
consoles with a bottle of Pedialyte (per physician’s orders). His anterior fontanel is slightly
depressed and posterior fontanel cannot be palpated. You auscultate regular breath sounds at
a rate of 24 breaths/min. No adventitious sounds. Pulse oximetry is 98% on room air. Heart
rate is 140 beats/min with regular rate and rhythm. Brachial and pedal pulses are +3 and equal.
Abdomen is round and nontender to palpation. Positive bowel sounds. Diaper is dry. S. B.
moves all extremities and there are no rashes noted. Rectal temperature is 98.9F. There is a
quarter-sized flat red area on occiput that “has been there ever since he was born” according to
his mother. Slight “tenting” noted.
You transport S. B. to radiology and he vomits a large amount of clear fluid. Patient
returns to the room in his mother’s arms, awake and alert. The mother appears anxious and
states, “I don’t know what’s wrong with my baby! Why can’t you people tell me anything?”
2. Your institution uses electronic charting. Based on the assessment described, which of the
following systems would you mark as abnormal as you document your findings? State your
abnormal findings and provide a brief narrative with the abnormal finding.
3. The emergency physician orders a complete blood count, complete metabolic profile,
urinalysis, blood pH, and x-rays. The physician suspects dehydration and metabolic alkalosis
secondary to hypertrophic pyloric stenosis. Which of the laboratory findings would you expect
with metabolic alkalosis?
a. Na: 128 mEq/L, K: 2.6 mEq/L, Cl: 90 mEq/L, HCO3: 28 mEq/L
b. Na: 130 mEq/L, K: 5.7 mEq/L, Cl: 94 mEq/L, HCO3: 22 mEq/L
c. Na: 130 mEq/L, K: 3.9 mEq/L, Cl: 98 mEq/L, HCO3: 17 mEq/L
d. Na: 148 mEq/L, K: 4.1 mEq/L, Cl: 108 mEq/L, HCO3: 13 mEq/L
4. What is the underlying cause of S. B.’s diagnosis of metabolic alkalosis?
5. Which of these clinical manifestations might you find with metabolic acidosis? Select all that
a. Increased respiratory rate
c. Increased risk for seizures
e. Neuromuscular irritability
S. B. is diagnosed with hypertrophic pyloric stenosis, admitted to the pediatric unit and
scheduled for surgery.
6. S. B.’s parents are concerned that their living situation contributed to S. B’s diagnosis. How
would you respond to their concerns?
7. Which of the following preoperative orders would you question?
Vital signs q 4h
Strict intake and output (I & O)
30 mL Pedialyte q3 h PO
Place IV and begin D51/3NS at 50mL/hr
Nasogastric (NG) tube placed to low continuous wall suction
8. You note that your patient was hypokalemic and the fluids you hung per doctor’s orders do
not include potassium. You contact the surgeon to clarify. You receive the following order:
“Discontinue D51/3NS at maintenance and hang D51/3NS with 20 mEq KCL/L at maintenance.”
You obtain the new fluids and hang per orders.
True or False: This is an appropriate nursing action. Explain your answer.
9. What postoperative teaching would you provide them?